Free-opening side stitched book and method of making same



June 17, 1941. R. E. ACKLEY 2,245,891

FREE'OPENING SIDE STITCHED BOOK AND METHOD OF MAKING SAME y Filed Nav. 19, 193s 2 Sheets-Shea?I 1 Fig. 7

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/N VEN TOR Patented `lune 17, 1941 Teo STT FREE-OPENING SIDE STITCHED BOOK AND METHOD OF MAKING SAME 6 Claims.

This invention relates to improvements in the class of books in which the pages are held together primarily by stitches passing transversely from side to side of the book close to the back margin. The stitches may be of either wire or thread. If of wire, theV binding process is known as side-wiring to distinguish it from saddlewiring, in which the stitches pass through the back fold of a folded group of pages. If of thread, the process is usually called side-sewing, either lock-stitch or chain stitch. In addition, various special types of stitch may be employed.

In another style of binding, very generally used for relatively expensive books, the pages are held together by stitches or sewing passing through the back folds of signatures, the stitches being interlocked from signature to signature. This style of Ibook is generally called Smythesewed, altho the actual sewing may be done on other than Smythe machines. As they come from the sewing machine, such books have nearly perfect opening quality, that is, when the book is opened the pages will lie almost perfectly iiat. Unfortunately, in this condition the books are very deficient in strength. In order to strengthen the books, a layer of glue and crash is usually applied'to the back. 'Ihis layer impairs the opening quality to some extent, and

the heavier and stronger the reinforcing layer,

the more the opening quality is impaired. Books of this kind must be handled with care to avoid breaking the back, that is, Icracking the layer of reinforcing material at the back. When subjected to unusually severe service, as in libraries or in the case of text books, they break down rapidly.

Side-stitched books have the advantage of great strength and resistance to hard service without breaking down. They are also considerably cheaper to manufacture. Side-wiring is therefore widely used for magazines, pamphlets, small telephone directories, trade catalogs etc. Side sewing has been increasingly used for school and reference books which receive severe usage. I-Ieretofore, however, side stitched books have suffered from the disadvantage of very poor opening quality. In many cases they will not lie open at all without being held. If they do lie open, the pages are so strongly arched that it is diicult to read the printing, especially the portions nearest to the center line of the book. In many cases it is necessary to exert continuous pressure in order to hold the pages suciently flat to read with any comfort.

A principal object of my invention is torenove this disadvantage, and to produce a side stitched book in which the pages lcan beheld flat and in a condition to be easily and Acom- Vfcrtably read, without the exertion of more pressure than is necessary to support the book.

A further object is to produce a book of this type which will lie open without being held.

Another object is to produce a free-opening side stitched book in which the pages are rmly and securely held, and which will withstand severe usage,

A further object is to economize on the amount of paper required to carry a given amount of text, by reducing the width of those portions of the inner margins of the pages which areon too steep an angle to carry printing; this economy being realized either by increasing the width of the lines of type on a page of given size, or by printing the same type on pages of less width.

Another object is to construct a book of this type which can be manufactured with a minimum departure from standard bookbinding methods.

Other advantages will appear more fully as I proceed with my specification.

In the accompanying drawings- Fig. 1 shows a side stitched book made according to my invention.

Fig. 2 shows a portion of a side stitched book made in the ordinary way, for comparison.

Fig. 3 is an end View of a prepared signature, showing the bend lines.

Fig. 4 shows a modified type of bending of the signature.

Fig. 5 shows another modification of the signature. i

Fig. 6 is a cross-section of a group of formed signatures, assembled to form a book and with stitch inserted.

Fig. 7 is a diagram illustrating the nesting of paper on a bend line.

Fig. 8 is a partial isometric view of a closed 'book with wire stitch inserted on the primary fold line.

Fig. 9 shows a similar book, sewed on the primary bend line.

Fig. l0 is a partial end View of a group of signatures, joined with a longer stitch than normally used. p K

Fig. 11 is a partial end View of the same book, opened.

Fig. 12 shows a similar book with flexible stitch placed closer to the rear margin.

Fig. 13 is a diagrammatic cross section showing a method of producing the bend lines in the signatures.

Fig. 14 shows the same parts in closed position.

Fig. 15 illustrates the nesting of paper on a bend line,

Fig. 16 shows the non-nesting or parallel-faced type of bend in a group of sheets.

Inasmuch as several factors are involved in the production of free-opening books by my method, which may be present in varying proportions in any given case, a brief discussion of these factors will aid in the understanding of the description which follows.

When a pile of loose or folded sheets of paper, such as comprise a book, is put under pressure, the rst result is to permanently set the folds if present, eliminate air from between the sheets, and flatten them out so that the pile is com;- pacted together. After this point is reached, however, the pile will still continue to yield u nder increasing pressure; but when the pressure is released, the pile will return approximately to the original thickness, and will continue to do this even tho repeatedly compressed. It behaves in fact like a very stiff spring. It is therefore possible to drive wire stitches so hard, or tighten thread stitches to so great tension, that the paper at the stitch line is heavily compressed, and the thickness of the book at the stitch line materially less than in the body of the book where it is not under pressure.

The principle involved in book stitching has sometimes been called the vise grip, and it has been assumed that the object of stitching is to immobilize the rear portion of the book, at and behind the stitches, so that the leaves cannot move, or as nearly as possible to fuse this rear margin into a solid mass. Some binders therefore drive wire stitches very hard, and pull up side sewing almost to the breaking point of the thread, under the impression that this increases the strength of the book. For the same reason, reinforcement is frequently glued tothe back of the book, or the latter is glued to the back of the case or cover in cased-in books.

A careful analysis of the forces brought into play in the handling of books shows that the above theory of stitched books is a misconception.

It is desirable that the pages should not be so loosely held that they can readily be torn out bodily, and so that the book will be firm when closed. For this reason, the stitches should not be too loose; but the real strength of the book is not dependent on this initial tension of the stitches, but is developed during the opening of the book.

Nearly all the strains which result from the use or abuse of a book are turning moments, and they result in a bending or prying action in the binding. This is true of opening a book; in a side stitched boolk the two portions of the book become levers and the stitches fulcrums upon which the levers turn. The long arms of the levers are represented by the portions of the leaves which lie in front of the stitches, and the short arms by the portions back of these stitches. Altho the fact that a true lever action is involved is masked by the flexibility of the leaves, the weight of the pages alone in a fair sized book may produce a tension of several pounds in the stitches when the book lies open. Because of the high ratio of the long to the short arms of the leaves, the tensile stress produced in the stitches is many times the weight of the paper.

Turning moments are also produced by pressing heavily upon the opened book to force the pages to lie flat; by piling books on an opened book, whether face up or face down; by reversing the book or turning the opened portions through a half-circle, so that the book can be held in one hand; and by pulling on the opened portions or otherwise trying to break down the resistance of the pages to opening in a flat condition.

However the strain may be produced, when the stress is great enough the two portions of the opened book will separate at the stitch line, and portions of the stitches will be Visible. In this case, the original compression of the paper by the stitches has been entirely overcome; instead of the stitches pressing inwardly against the paper, the latter now presses outwardly against the stitches.

The tension in the stitches produced by opening or forcing the book is matched by an equal compression in the material back of the stitch line. If no reinforcement is applied to the back of the book, this results in elastically compressing the paper at the back so that the latter is narrower than the thickness of the body of the book. If a stiif and unyielding reinforcement is used, the compressive stress produces a strain in the reinforcing layer, but no perceptible narrowing of the bac'k.

An improvement in opening quality may be effected by suitable choice of the above factors alone. Fig. 10 represents a portion of a book comprised of signatures and joined by stitches I9. Fig. 11 shows the same book in opened condition. In Fig. 10, the length A of the stitches is but little less than the length B of the back of the book, in which condition the tension of the stitches is sufficient to hold the pages rmly in contact when the book is closed, but not sufficient to heavily compress the paper. The width B of the back in turn is approximately equal to the thickness C of the body of the book. When the book is opened, the leverage of the opened portions produces a tensile stress in the stitches, which are relatively inextensible, and an equal and opposite compressive stress in the material back of the stitch line. Since this material is somewhat compressible, as above described, the length B of the back of the opened book is less than the length B when the book is closed, less .than the length A of the stitches, and less than the normal thickness C of the body of the book. The curve described by the opened leaves, therefore, instead of starting with a substantially vertical portion 20 (Fig. 2), now starts with the rearmost portion at an angle, as at 2| or 22. Thus the relatively flat portion of the curve is more quickly reached, so that the printed text can be kept on this relatively at portion and therefore be more easily read'. Since, under given condi tions of thickness of book and pressure exerted in opening, the amount of elastic compression of the book is relatively a iixed quantity, it is obvious that the angle at which the leaves start their curvature depends on the distance E or E from the stitch line to the back of the book. The closer the stitches are to the back of the book, the greater this angle becomes.

When sewing or other flexible stitches are used, and the stitches are placed relatively close to the rear margin of the book, as at I9 in Fig. 12, and of a length to hold firmly but not heavily compress the paper, the back of the book on opening aSSllmeS an arched shape which still further improves the opening quality. When the book is opened, the point of opening is the high point of the arch, so that the central pages are at a higher level than the outer pages. The thickness of the pile of pages on either side of the center therefore does not interfere to the same extent as with a nat back, with the curvature of the central pages.

Besides the compression at the back, there is also a compression of the paper at F, F', when the book is opened, so that the sum of these two dimensions is less than the width B or thickness C of the body of the closed book.

In order to permit the action above'described, it is necessary either that no reinforcement be applied to the back of the book in completing the binding, or if reinforcement is used, it must be so flexible, yieldable or elastic, that the compression of the paper and narrowing of the baclk as described is not interfered with.

The improvement in opening quality secured by the means above described is limited, since a pile of paper when bent or curved normally assumes a condition in which the two faces of the pile are parallel, as indicated at 23, 24 in Fig. 2, or 25, 26 in Fig. 11. Therefore, no matter how short the radius of curvature of the concave side of the pile, the convex side cannot have a radius of curvature less than the thickness of the pile, plus the radius of the concave side. In a thick book opened near the center, there is necessarily a pronounced curvature of the surface near the center when the back is held relatively fiat and without arching, as is the case in side stitched books as previously made.

Nevertheless, especially in the case of relatively thick books side sewed or otherwise stitched with flexible stitches, a marked improvement may be secured by use of the above method. The essentials of this method are; the back must be left without rigid reinforcement, and free to compress when the book is opened or forced; the length of the stitches must be regulated, so that while the pages arefirmly held when the book is closed, they are still longer than the thickness of the compressed back when the book is opened; and the stitching should be placed as close to the .ba-ck margin of the book as is consistent with maintaining the strength of the bindingthat is, the compressive strength of the back should not be less than the tensile strength of the stitches. The distance from the back of the book to the stitching which corresponds with equality of strength for compressive and tensile stresses can be found by test in individual cases.

While I prefer to rely chiefly on other means, to be described, for securing free opening in side stitched books. the above means may be employed either by themselves, or be combined to a greater or lesser extent with these other means and thus contribute to the final result.

As above mentioned` when a pile of paper is curved or bent as a whole, it tends to assume a condition in which the two faces are parallel to each other, as at 23, Z4 of Fig. 2, or at I4 in Fig. 16. If each individual sheet of the pile is so strongly bent as to permanently hold the bend, however, the paper can be nested, as at I3 in Fig. 15; and in this case the whole pile can be caused to change its direction abruptly instead P of through a wide arc as in the parallel-faced bend. In this case the surfaces of the pile `are not parallel throughout. As indicated diagrammatically in Fig. 7, the distance G from surface to surface of the pile is greater than distance I-I taken at any point normal to the surface and away from the bend. Mathematically, the relation can be expressed as that distance G is equal to distance H times the secant of the angle a. For moderate angles the increase in thickness at the bend line is small; for example, if G is equal to 1 and angle a is 15 degrees, H equals 1.03531; if angle a is 24 degrees 37 minutes, I-I equals 1.1 or ten per cent more than G. The total change in direction is twice the amount of angle a, so that with an increase of thickness at the bend line of Sil/2%, a pile of paper may be abruptly bent through an angle of 30 degrees, and with 10% increase, through an angle of 49 degrees 14 minutes.'

In the preferredform of my invention, the signatures cr groups of leaves I, Fig. 3, are formed with bending lines parallel to and adjacent the rear edge 2 of the signature. The principal bending lines are the primary bend 3, and the secondary bend 4, parallel to but further away from the back and opposite in direction to the primary bend. Supplementary .bends 5, 6 may also be formed in order to facilitate the bending operation and to maintain the surfaces of the signature in the same general plane, but these supplementary bends are not essential to the practice of the invention and may be omitted, as in Figs. 4 and 5.

The bends are preferably formed with greater angles than will exist in the finished book, in order to set the bend and also to cause the paper to assume the sharpest angle possible when the book is opened. After forming the Ibends, the signature may Ibe pressed or passed between rollers, if desired, to lessen the abruptness of the bends; or the signatures may be' assembled to form a book and compressed as a group. If not previously flattened out, when the stitches are formed of a predetermined length, the bends will be flattened to an angle consistent with the length of the stitches.

It is necessary that the primary bend, and preferably the secondary bend also, be of the nesting type shown at i3 in Fig. 15. It is imma.- terial whether the supplementary bends are of the nesting or parallel-faced type. The bends may ,be formed inany desired manner, as by compressing the rear margin of the signature between formed surfaces as shown in Figs. i3 and 14. In these figures, clamping surfaces ii, i hold the signature firmly in position While the formed surfaces 8, 9 compress the rear margin of the signature to form the bends. One of the surfaces may have an extended lip I@ with sloping surface II, which as the surfaces approach each other forces the portion of the signature in'which the bends are to be formed into the arched shape I2. This facilitates forming sharp Ibends in each leaf of the signature when the formed surfaces come together, since slightly more paper is required to form sharp bends as at I3 rather than round bends as at I4. The arch in the paper provides the needed extra material.

The surfaces 8, 9 may be formed in fiat dies, or in rolls between which the rear margin of the signature passes. The clamping surfaces 6, 'l may likewise .be either fiat bars or rolls.

The above described method is satisfactory for forming the nesting-type bends in the signatures or other groups of pages, but any other means of forming such bends may be employed.

When the signatures I, I. have been prepared as described, they are assembled in the usual manner to form a book, along with any inserts, end sheets, etc., which may be desired, and which have been formed with bends in the same manner as the signatures proper. All this material, when assembled, nests along the bend lines as indicated in Fig. 6, and the group is then stitched along the primary bend line 3. In Fig. 6, I5 represents a wire stitch joining the signatures. In order to bring out the nesting of the material clearly and to show the effect of the nesting on the length of the stitches, the angles have been exaggerated somewhat over those which would exist in the nished book in practice. Ordinarily the angle a will be from 15 degrees to 2O degrees in the closed book. In the opened book, the angle is greatly increased.

If desired, instead of inserting wire stitches I5, sewing I6 may be used to join the signatures, being placed along the primary bend line 3 in the same manner as the wire stitches.

Whether of wire or thread, the length A of the stitches must be regulated to correspond with the thickness of the book on the primary bend line 3, which as above explained is greater when the paper is nested than when the faces of the book are parallel. When paper is nested as shown, it olers considerable resistance to compression along the bend line, hence one way of regulating the length of the stitch is by limiting the tension produced in the stitches. In the case of wire stitches, the distance between the driving head and the anvil of the stitching mechanism, at their nearest approach, may also be regulated, as likewise the distance between the presser foot and base of a sewing machine.

The length of the stitches should be such as to hold the leaves rmly together when the book is closed, but not short enough to eliminate the nested formation along the primary bend line 3.

When a book made in this manner is opened, as shown in Fig. l, the leaves in the right hand portion of the book tend to swing about the primary bend line 3, and to assume the relatively flat surface shown, so that the text I1 may be easily read, including the portion I8 nearest to the center. Similarly the leaves of the left hand portion tend to swing about the secondary bend line 4 and to nest together as indicated at 21. 'I'he book has no tendency to spring closed, as is characteristic of books side stitched in the ordinary way. With side stitched books as heretofore made also, the portion I8' of the text is often on a pronounced slope, and therefore foreshortened and diincult to read.

To summarize the advantages of nesting the paper along bend lines and stitching through one of the lines; the stitches are longer than would be employed if the paper were not nested, so that when the book is opened, the paper is free to re-adjust itself and assume the position best adapted to at opening; if rigid reinforcement on the back is avoided, the back will compact together on opening so that the leaves have a better starting angle; in spite of the longer stitches, nesting causes the leaves to be held rmly when the book is closed; nesting permits the leaves to change their direction abruptly at the bend line, so that the portions of each page on which the text lies can be kept relatively fiat.

In the above description, signature has been used as a convenient generic term to describe any group of leaves which is to form part of a book, however the leaves may be folded or otherwise combined together. Since the state of aggregation of the leaves is immaterial to the result, groups of loose leaves, single leaves, end sheets whether single or folded and whether or not attached to the outside signatures, inserts, etc., are fully equivalent to signatures in the practice of this invention.

Books made as above described may be bound in any desired manner. For example, paper covers may be formed around the book and glued to the back; or the book may be cased-in with or without rounding and backing. Reinforcement may be omitted from the 4back or applied; in the latter case, the narrowing of the back when the book is opened is more or less interfered with, but there is still a great gain in opening quality due to the nested formation of the paper, which causes an abrupt change in angle in the paper which would otherwise require a wide arc to accomplish. Since a page in a side stitched book must change its angle, roughly, through ninety degrees in order to reach the at level of the opened book, the shorter the distance in which this can be accomplished, the more of the page will be in suinciently fiat condition for text to be easily read.

It will be evident that many modifications of the book and method described may be made without departing from the spirit of my invention. For instance, the stitching may be placed closer to the back margin of the book than the primary bend line, depending upon the additional space available when the book is opened to permit the pages to nest and change their angle abruptly. If this is done, in the case of thin books the bend lines may be established in the leaves after the book has been stitched instead of before. Many other modications may be made within the scope of my invention. I therefore do not wish to confine myself to the specific embodiments shown or described and claimed, but to claim all novelty inherent in the invention as broadly as permissible, in view of the prior art.

What I claim as new, and desire to secure by Letters Patent, ist

l. In aV free-opening side stitched book composed of leaves, stitches placed on a line parallel to and adjacent the back margin of said book, and means comprising a nested formation of said leaves on the stitching line to cause the effective thickness of said book on said stitching line to be greater than the thickness of the body of said book, said stitches being of a length intermediate between the uncompressed and the compressed thickness of said book at the stitching line.

2. In a free-opening side stitched book com- .posed of leaves, an indented bend line in each of said leaves, said 'bend line being parallel to and adjacent the rear margin of said leaves, said leaves being nested on the bend line, and stitches passing transversely from side to side of said book on a line substantially coincident with said bend line.

3. In a free-opening side stitched book composed of leaves, primary and secondary indented bend lines of opposite direction in said leaves, said bend lines being parallel to and adjacent the back margins of the leaves and with the primary bend line nearest thereto, said leaves being nested on the bend lines, and stitches passing transversely from side to side of said book on a line substantially coincident with said primary bend line.

4. In a free-opening side stitched book composed of leaves, primary and secondary indented bend lines of opposite direction in said leaves, said bend lines being parallel to and adjacent the back margins of said leaves and with the primary bend line nearest to said back margins, said leaves being nested on the bend lines, and sewing passing transversely from side to side of said book on a line substantially coincident with said primary bend line.

5. In a free-opening side stitched book composed of leaves, primary and secondary indented bend lines of opposite direction in said leaves, said bend lines being parallel to and adjacent the back margins of said leaves and with the primary bend line nearest to said back margins, said leaves being nested on the bend lines, and stitches passing transversely from side to side of said book on a line substantially coincident with said primary bend line, said stitches being of a length intermediate between the uncompressed and the compressed thickness of said book at the stitch line.

6. The method of making a free-opening side stitched book composed of signatures, which comprises clamp-ing each of said signatures along a line parallel to but spaced away from the back margin of said signature, forcing the material between the clamping means and the back margin into a bowed shape, compressing said material between formed faces to form sharply inflected bend lines along which the individual leaves comprising said material nest, said bend lines comprising a primary bend line relativelyclose to the back margin and a secondary bend line further removed from said back margin, subsequently attening said formed material to reduce the sharpness of the inflections, gathering a plurality of said signatures in nested relation, and stitching said book along a line substantially coincident with said primary bend line, said stitching being composed of stitches of a length intermediate between the uncompressed and the compressed thickness of said book at the stitch line.

RAYMOND E. ACKLEY. 

